Abstract
We measured the ascending spinal cord evoked potentials (ASCEPs) in 65 spinal surgery or spinal cord surgery cases. In 11 spinal cord tumor patients (age, 18 to 73 years ; average 51.6 years.), the relationships among the changes in intraoperative ASCEPs, spinal cord function, and postoperative outcome were analyzed. The control group included 54 spinal surgery or spinal cord surgery patients who underwent intra-operative ASCEP monitoring. The typical ASCEPs consisted of 2 negative peaks (N1, N2) . Before spinal cord decompression, N1 showed, 0.7 to 7.5μV (averaged 2.7μV) in amplitude ; this peak apparently increased after laminectomy and dural incision (0.8 to 15.9μV, average 4.8μV after dural incision) . Post-operatively, the motor score recovered from 4.3 points to 5.0 points and the recovery rate was 16.9%. On the other hand, the sensory score recovered from 6.6 points to 9.2 points and the recovery rates was 71.2%, indicating that more sensory recovery was obtained by the surgery. If the patients were separated to an H group (amplitude increased to more than 200%) and an L group (less than 200%), the post-operative recovery rate of the sensory score was apparently dominant in the H group (H group, 118.8% ; L group, 41.9%) . Thus, the prospect of good post-operative outcome seemed possible with ASCEP monitoring applied during spinal cord tumor surgery.
